Pressure Optimization in Pneumatic Interfaces Using a Single-Bay Seven-Story Infilled Reinforced Concrete Frame: Experimental and Numerical Investigation

Reinforced concrete infilled frames have been studied over the years along with the infilled openings. To resist the lateral loads that are applied on the frames, stress is transferred from the reinforced concrete (RC) to infill, which leads to brittle collapse. The conventional interface medium, which was considered by researchers and recent studies, was prepared by changing the interface materials between the RC frame and infill panels to different elastic materials. This study focuses on optimizing the interface pressure using a butyl rubber tube, which reduces the stress distribution to the infill panel from the RC frame. A 50% window opening was adopted in this study, which is the optimized size from previous research. The optimization patterns followed linear and nonlinear patterns, such as the same pressures in all stories and varying pressures in all stories. The third story had a 8 PSI pattern and the other stories had a 2 PSI pattern; all stories with 8 PSI patterns achieved the least displacement when compared to other variations. A monotonic static analysis was performed for both the experimental and analytical study. The boundary conditions were pinned, and coupling interfaces were made for the master and slave surfaces. The pressure conditions were applied in various linear and nonlinear patterns to optimize the pressure. A comparative study was performed on the displacement, stiffness, and drift ratio for the critical position of the interface pressure in both the analytical and experimental studies. The difference was approximately 0.53% in the analytical study and 0.37% in the experimental work. The optimization was performed using both an experimental model and an analytical model, which had an error percentage of 0.61%.